Just wondered why you would want a non compensating instrument - is it the reduced weight?? Given the choice I wouldn't bother with non compensators except for the smallest of beginner students and even then the use of stands could be used to make the playing posture more acceptable

Compensating Eb Basses and Euphs are largely wasted in a Brass Band.
The register(s) where compensating is useful is from low F below the staff (treble clef) to low Db a semitone above pedal C. Then again the octave below that.

Weight, as you say, is a factor. Marching with a tuba is not great fun on the whole.

Clarity through the 4th valve is improved since the 4th valve slide isn't routed back through the main block (never mind all the contortions of the airstream when you need 4th PLUS another valve on a compensator...).

If you've played a good one, you'll know they respond faster (ie more agile). The valves are quicker since there's less mass to shift up-and-down.

Most importantly though is the lack of need for the compensating system in nearly all band-writing for Eb basses (this is equally true for Euphoniums too). When was the last time you saw anything below a low F# which didn't have the top Eb Bass 8va? Perhaps guys playing a lot of very modern music use these notes frequently but I doubt it. Only perhaps in this Century have composers/arrangers dared to presume bands have a bass section with 4 valve instruments. The other reason you don't find these notes is because the Bb Basses cover the Eb Bass compensating range.

Tuning-wise, non-comp instruments with the 4th valve tuned well for the under-staff D would do most players just fine. If you like £50-or-so will get you a 1st and/or 3rd valve triggers.

Guys who do a lot of modern solos with band will make good use of the compensating register. Equally, players in Orchestras and Wind Bands make good use of them, but not in bands...